If you want to see what Wikipedia has to say about this, I suggest the article entitled "Formation and evolution of the Solar System".
It was Nicolaus Copernikus. Type it into Wikipedia for more info.
there are 9 planets
No, those are the outer planets.
There are 4 rocky planets and 4 gaseous planets in the solar system
they are larger but not rockier then the inner planets the outer planets are made of gas.
Ah, there is so much to learn about the Solar System. It's very Easy to search Facts about Planets. You just go to Wikipedia on the Internet and type in "Planets"
You can look up information on the individual planets on Wikipedia. I am not sure the information is readily available as a ready-made list, so you may have to compile it yourself. The revolution around the Sun is listed as "orbital period".
It was Nicolaus Copernikus. Type it into Wikipedia for more info.
there are 9 planets
the inner planets made up of rocks while the outer planets are made up of gases and liquids.
All the planets are made of "matter" and that has "mass".
Go to Wikipedia and search the article "Extrasolar planets". It has links to several lists of planets and planetary systems.
Type your answer here... all planets are made of gasses
Wikipedia was made/started on January 15 2001 by Jimmy Wales and Larry Sanger.
The planets Mercury, Venus, Earth, and Mars are made of rock.
They are made of less dense materials. While the inner planets are made primarily of rock, the outer planets are made mostly of hydrogen and helium.
They are made of less dense materials. While the inner planets are made primarily of rock, the outer planets are made mostly of hydrogen and helium.